Quasi-two-dimensional (quasi-2D) perovskite light-emitting diodes (PeLEDs) are considered as one of the most potential candidates in electroluminescence territory owing to their unique quantum confinement effect and excellent thermal stability of the light. Nevertheless, heterogeneous energy domain distribution leads to severe non-radiative recombination in the process of energy transfer, which enormously hinders the performance and application of PeLEDs. Herein, an ambipolar amino acid, 5-aminovaleric acid (5AVA), is demonstrated to be able to coordinate lead and halides simultaneously with its carboxyl and amidogen groups. The coordinated ambipolar molecule not only reconstitutes energy domains of perovskites but also minimizes the interfacial defects of PeLEDs. Accordingly, the presence of 5AVA in perovskite precursors leads to dramatic suppression of the n = 1 and n = 2 phases and accelerates energy transfer from wide bandgap domains to narrow bandgap ones. As a result, maximum external quantum efficiency (EQE) of 19.3% (18.20% ± 1.10%) is achieved in quasi-2D green PeLEDs with current efficiency of 61.7 cd A⁻¹.

中文翻译：

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具有双功能氨基酸的高效准二维绿色钙钛矿发光二极管

准二维（quasi-2D）钙钛矿发光二极管（PeLED）由于其独特的量子限制效应和出色的光热稳定性，被认为是电致发光领域最具潜力的候选材料之一。然而，异质的能量域分布导致能量转移过程中严重的非辐射复合，极大地阻碍了PeLED的性能和应用。在此，双极性氨基酸 5-氨基戊酸 (5AVA) 被证明能够同时与其羧基和酰胺基团配位铅和卤化物。协调的双极性分子不仅重构了钙钛矿的能量域，而且还最大限度地减少了 PeLED 的界面缺陷。因此，n  = 1 和n  = 2 相并加速从宽带隙域到窄带隙域的能量转移。结果，在电流效率为 61.7 cd A ^-1的准二维绿色 PeLED 中实现了 19.3% (18.20% ± 1.10%) 的最大外部量子效率 (EQE) 。